Electrical connector



April 12, 1966 e. s. FARISON 3,246,284

ELECTRICAL CONNECTOR Filed April 2, 1963 2 Sheets-Sheet 1 INVENTOR. 517777 6 )Zrzxa 71.

A ril 12, 1966 s. s. FARISON 3, 8

ELECTRICAL CONNECTOR Filed April 2, 1963 2 Sheets-Sheet 2 INVENTOR.6/9777? 6', i'krzzs'aw /W M11 HM United States Patent 3,246,284ELECTRICAL CONNECTOR Glenn S. Farison, Southfield, Mich, assignor toChrysler Corporation, Highland Park, Mich, a corporation of DelawareFiled Apr. 2, 1963, Ser. No. 269,905 4 Claims. (Cl. 339-223) Thisinvention relates generally to detachable electrical connectors and moreparticularly to a detachable electrical terminal particularly suited forconnecting an ignition cable to a spark plug of an internal combustionengine.

In the past, various designs of ignition cable terminals have beenemployed many of which were formed from flat metal blanks to provide, atone end thereof, a connecting portion of generally hollow cylindricalshape for circumferentially engaging the terminal of a spark plug. Agenerally axially extending slot, resulting from the forming operationof the connecting portion, provided a means whereby some resiliencycould be experienced in the connecting portion for purposes of eitherconnecting or disengaging the cable terminal from the spark plugterminal.

Such resilient connecting portions have not been entirely satisfactorybecause the tendency is to bend and permanently distort the connectingportion especially during disengagement of the cable terminal from thespark plug terminal.

Accordingly, it is an object of this invention to provide a detachableelectrical terminal having a relatively resilient connecting portion andmeans for preventing the resilient connecting portion from becomingpermanently distorted.

Another object of this invention is to provide, in a detach'ableelectrical terminal, a relatively resilient connecting portion formed toprovide means for prevent-ing permanent distortion thereof and means forurging the connecting portion generally radially inwardly.

Other objects and advantages of this invention will become apparent whenreference is made to the following description taken in conjunction withthe drawings wherein:

FIGURE 1 is a plan view of a partially formed blank used in forming adetachable electrical connector according to the invention;

FIGURE 2 is a cross-sectional view taken substantially on the plane ofline 2-2 of FIGURE 1 and looking in the direction of the arrows;

FIGURE 3 is a side elevational view of the detachable connector withportions thereof broken away and in cross-section showing a spark plugterminal received therein;

FIGURE 4 is an end view of the ignition cable-receiving portion of theconnector shown in FIGURE 3;

FIGURE 5 is an end view of the connector taken substantially on theplane of line 5-5 of FIGURE 3, with the spark plug removed, and lookingin the direction of the arrows;

FIGURE 6 is a side elevational view of a spring clip employed inconjunction with a modified form of the invention;

FIGURE 7 is a fragmentary end elevational view of the spring clip ofFIGURE 6 taken generally in the direction of the arrow in FIGURE 6;

FIGURE 8 is a fragmentary cross-sectional view taken on the line 88 ofFIGURE 5, looking in the direction of the arrows, illustrating thecooperative action between the spark plug terminal, detachable connectorand the spring clip in the modified form of the invention; and

FIGURES 9, 10, 11 and 12 are views similar to FIG- URES 1, 3, 5 and 8,respectively, illustrating another form of the invention.

Referring now in greater detail to the drawings, FIG- URE 1 illustratesa partially formed terminal or connector blank 10 which is subsequentlyformed to assume the configuration generally shown by FIGURES 3, 4 and5.

The blank 10 is formed of generally rectangular body portions 12 and 14which are connected to each other by means of an integrally formedmedial bridge or connecting portion 16 of relatively reduced width. Bodyportion 14 is preferably formed to have transversely directedcorrugations or convolutions 18 which are provided with a plurality ofindentations 20, two of which are shown in FIGURE 2. Preferably, theindentations are formed in a plurality of substantially aligned rows butin staggered relationship as between successive rows.

Transverse ends 22 and 24 of body 12 are formed, as by notches orcut-out portions 26, to provide laterally extending and oppositelydirected projections 28, 30 and 32, 34, respectively. Projections 28 and33 are then bent slightly downwardly from the plane of the blank 10while projections 32 and 34 are bent slightly upwardly. It is notabsolutely necessary that the various projections be bent in preciselythe direction stated. In fact, the respective directions'rnay bereversed depending on the subsequent sequence of operations to beperformed on the blank 10 as will be apparent from the followingdescription thereof.

Metal blank 10 is subsequently curled, generally about its longitudinalaxis 36, until body portion 14 assumes a generally U-shape asillustrated by the end view thereof in FIGURE 4. Body portion 14 beingthusly formed is suited for the later reception therein of one end of anignition cable 38 shown in phantom lines in FIGURE 3. The upper ends 39and 41 of the U-shaped body portion 14 are later curled inwardly towardeach other, as illustrated generally in phantom lines in FIGURE 4, inorder to contain the ignition cable 38 therein and establish electricalcontact, for example, by means of internally engaging an overcurledextension 37 of the electrical conductor or conductors containedtherein. Cable 38 will, of course, as illustrated in FIGURE 3, generallyassume the form of the convolutions or corrugations 18.

Simultaneously with the forming of body 14 into a U-shape, the medialconnection portion 16 and body portion 12 are also curled. The medialportion 16 is formed to assume a generally arcuate cross-sectionapproaching a semi-circular configuration. Body portion 12, however, isspirally curled so as to form a generally cylindrical barrel orconnecting portion 40 which is closely received about a spark plugterminal 42.

It is necessary to establish a particular relationship during theformation of the barrel. That is, the transverse end portions 22 and 24must be curled in a manner which will result in having the projectionsfirst described as being bent upwardly assume an uppermost positionrelative to those projections first described as being bent downwardly.Accordingly, with reference to the blank 10 illustrated in FIGURE 1,body portion 12 would be curled into a generally cylindrical form so asto have projections 32, 34 and end portion 24 disposed above or on theouter arcuate surface of end portion 22 as shown in FIGURE 5.

The tabs or projections 28, 3t), 32 and 34 may be originally bent toassume a relationship different from that described. For example, tabs28, 3t) and tabs 32, 34 could all be downwardly bent from the plane ofthe blank.

Body. portion 12 could then be curled so as to have end 22 pass underend 24 and when tabs 32 and 34 reached a position of generaljuxtaposition with the slots 26 of end 22, tabs 32 and 34 could be bentinwardly generally toward the center of the curled body portion 12. Byhaving all the tabs originally bent in the same direction, prior tocurling, the actual curling operation may be simplified by eliminatingpossible interference between the tabs during the curling operation. Y

The maximum size of aperture 44, as defined gene-rally by thebarrel-shaped body portion 12, is determined by the coaction of bentprojections or tabs 32, 28 and 30, 34. That is, as the barrel 40 isurged radially outwardly, end portions 22 and 24 are moved relative toeach other until tabs 28 and 32 as well as tabs 30 and 34 abut againsteach other to prevent further relative movement of end portions 22 and24.

Barrel 40 may be formed so as to have the cooperating tabs, such as 32and 28, spaced from each other when the barrel is in its free state. Insuch an arrangement, the tabs could move towards each other whenever aspark plug terminal is inserted within the aperture 44 urging the barrelradially outwardly.

It should be noted that slots or cut-outs 26 not only serve to form therespective tabs but also provide a space for the reception therein ofthe several bent tabs when body portion 12 is curled to assume agenerally cylindrical form as shown by FIGURE 5.

In view of the above, it can be seen that the provision of interlockingabutment tabs or projections will prevent an undue distortion of thebarrel or connecting portion 40 whenever the cable terminal isfrictionally disengaged from the spark plug terminal. It should be notedthat 'no amount of angular movement or twisting during the disengagementoperation will cause the aperture 44 or barrel 40 to become permanentlydistorted as occasioned with the prior art.

Another form of the invention contemplates the provision of anexternally positioned arcuate spring member generally engaging the outerperipheral surface of barrel 40. In the modified form of the invention,body portion 12 of blank is provided with an aperture 46 for receivingtherethrough the depression 48 of the spring clip 50 as illustrated inFIGURE 6 and fragmentarily in FIG URE 7.

FIGURE 5, having a fragmentary portion of the barrel 40 broken away,illustrates the manner of assembling the spring clip 50 to the barrel bymeans of causing projection or nib 48 to extend inwardly through theaperture 46.

FIGURE 8 illustrates in greater detail the engagement obtained asbetween the barrel 40, spring clip 50, projection or detent 48 and thespark plug terminal 42. Preferably, the detent 48 is of a width anddepth sufficient to engage tapered surface 52 (which in cooperation withshoulder 56 generally defines an annular recess) of termi nal 42 inorder-to firmly and yet resiliently engage the terminal and urge thebarrel 40 toward the shoulder 54 of the spark plug. In order to affectdisengagement, the cable terminal need only be pulled so as to cause thedetent 48 to be urged radially outwardly over the extreme diameter ofthe spark plug terminal. Aperture 46 is of a width which closelyreceives the detent 48 so as to substantially minimize any axialmovement of the detent 48 and clip 50 relative to the aperture 46 andbarrel 40.

The embodiment as shown in FIGURE 8, of course, retains all theadvantages of the cable terminal of FIGURE 4 without the provision of anexternal spring clip 50. However, the structure of FIGURE 8 containsadditional advantages as, for example, being able to provide a member(spring clip 50) for creating a strong locking force between the barrel40 and the spark plug terminal and yet preventing the application ofexcessive forces thereto during disengagement because of the confiningeffect of the barrel 40 and interlocking projections or tabs 32, 28 and30, 34.

FIGURES 9 through 12 illustrate still another form of i the invention.All elements which are like or similar to those of FIGURES 1-8 areidentified with like reference numerals.

Body portion 12 of blank 58 is provided with preferably two dimple-likeportions 60 and 62 raised from the surface thereof. Blank 58 and tabs28, 30, 32 and 34 are bent and formed similarly to blank 10 in order toassume spark 4 plug electrode-receiving barrel 40 as fragmentarilyillustrated in FIGURE 10.

FIGURE 11, an end view of the barrel 40, illustrates the inwardlydirected dimples or detents 60 and 62 as being located generally onopposite sides of a vertical plane passing through the longitudinal axisof the barrel 49. The relationship of the various elements shown inFIGURE 11 is substantially that achieved when barrel 40 is properlyengaged or seated onto terminal 42 of the spark plug. At this time, thecooperating tabs, such as 28 and 32, are spaced from each other adistance X, which allows for radial expansion of the aperture 44 andrelative movement of end portions 22 and 24, as caused by detents 60 and62 engaging the enlarged diameter of the spark plug terminal, during theprocess of engaging or disengaging the detachable connector from thespark plug. The cooperating tabs do, however, abut against each other inorder to permit only that expansion of barrel 40 necessary forengagement or disengagement and to prevent undue forces on the barrelwhich might cause permanent distortion thereof.

FIGURE 12, a fragmentary cross-sectional view taken on line 1212 ofFIGURE 11, better illustrates the interlocking relationship of thedetents 60 and 62 with the annular recess 64 of spark plug terminal 42.

Although but threeforms of the invention have been disclosed anddescribed, it is apparent that other embodiments and modifications ofthe invention are possible within the scope of the appended claims.

I claim:

1. A detachable electrical connector for forming an electricalconnection between an ignition cable and a spark plug terminal,comprising a generally U-shaped body portion adapted to be formed aboutsaid ignition cable in order to securely engage said cable, a spirallycurled body portion having overlapping ends forming a terminal-receivingopening, a connecting portion of arouate cross-section joining saidcurled body portion to said U-shaped body portion, a plurality ofcut-out portions formed on said curled body portion near said ends, anda plurality of tabs formed on said curled body portion near said ends,said tabs formed on the radially outermost overlapping end being bentthrough certain of said cut-out openings in a direction generally towardsaid terminal receiving opening, said tabs formed on the radiallyinnermost overlapping end being bent through other of said cut-outopenings in a direction generally away from said terminal-receivingopening.

2. A detachable electrical connector for forming an electricalconnection between an ignition cable and a spark plug terminal,comprising a first body portion adapted to be formed about said ignitioncable so as to be securely engaged thereto, a second body portion curledso as to have overlapping ends forming a terminal-receiving opening, aconnecting portion joining said body portions to each other, and aplurality of tabs formed on said second body portion near said ends,said tabs formed on the radially outermost overlapping end being bent ina direction generally toward the center of said terminal- -receivingopening, said tabs formed on the radially innermost overlapping endbeing bent in a direction generally away from said terminal-receivingopening, said tabs by virtue of their respective directions of bendbeing in position to abut against each other.

3. A detachable electrical connector for forming an electricalconnection between an ignition cable and a spark plug terminal,comprising a first body portion adapted to be formed about said ignitioncable in order to securely engage said cable, a spirally curled bodyportion having overlapping ends forming a terminal-receiving opening, aconnecting portion joining said curled body portion to said first bodyportion, a plurality of cut-out portions formed on said curled bodyportion near said ends, and a plurality of tabs formed on said curledbody portion near said ends, said tabs formed on the radially outermostoverlapping end being bent through certain of said cut-out portions in adirection generally toward said terminal-receiving opening, said tabsformed on the radially innermost overlapping end being bent throughother of said cut-out portions in a direction generally away from saidterminal-receiving opening.

4. A detachable electrical connector for forming an electricalconnection between an electrically conductive cable and a terminal of anelectrode, comprising a first body portion adapted to be formed aboutsaid cable in order to be securely engaged thereto, a second bodyportion spaced from and connected to said first body portion, saidsecond body portion having oppositely disposed end portions curled inorder to form a generally cylindrical barrel with a terminal-receivingopening therein adapted for detachable connection to said electrodeterminal, each of said end portions having first and second axial ends,and positive abutment means formed integrally with each of said axialends, said abutment means comprising a generally axially extending tabmember formed on each axial end of each end portion, at least 20 two ofsaid tab members being bent so as to be generally inclined with respectto the axis of said terminalreceiving opening in order to respectivelyabut against the other of said tab members thereby preventing an undueenlargement of the di-ametrical size of said terminalreceiving openingwhenever said cylindrical barrel is either being connected to ordisconnected from said terminal.

References Cited by the Examiner UNITED STATES PATENTS 906,806 12/1908Kortick et al. 1,566,465 12/1925 Champion 339-223 2,711,524 6/1955Beaver 339256 2,715,215 8/1955 Flora 339258 X 3,141,724 7/1964 Raymond339 256 FOREIGN PATENTS 604,880 7/1948 Great Britain.

JOSEPH D. SEERS, Primary Examiner.

PATRICK A. CLIFFORD, Examiner.

1. A DETACHABLE ELECTRICAL CONNECTOR FOR FORMING AN ELECTRICALCONNECTION BETWEEN AN IGNITION CABLE AND A SPARK PLUG TERMINAL,COMPRISING A GENERALLY U-SHAPED BODY PORTION ADAPTED TO BE FORMED ABOUTSAID IGNITION CABLE IN ORDER TO SECURELY ENGAGE SAID CABLE, A SPIRALLYCURLED BODY PORTION HAVING OVERLAPPING ENDS FORMING A TERMINAL-RECEIVINGOPENING, A CONNECTING PORTION OF ARCUATE CROSS-SECTION JOINING SAIDCURLED BODY PORTION TO SAID U-SHAPED BODY PORTION, A PLURALITY OFCUT-OUT PORTIONS FORMED ON SAID CURLED BODY PORTION NEAR SAID ENDS, ANDA PLURALITY OF TABS FORMED ON SAID CURLED BODY PORTION NEAR SAID ENDS,SAID TABS FORMED ON THE RADIALLY OUTERMOST OVERLAPPING END BEING BENTTHROUGH CERTAIN OF SAID CUT-OUT OPENINGS IN A DIRECTION GENERALLY TOWARDSAID TERMINALRECEIVING OPENING, SAID TABS FORMED ON THE RADIALLYINNERMOST OVERLAPPING END BEING BENT THROUGH OTHER OF SAID CUT-OUTOPENINGS IN A DIRECTION GENERALLY AWAY FROM SAID TERMINAL-RECEIVINGOPENING.